<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>盒子模型</title>
  <style>
       .box{

            /*
              margin
              padding
            left right top bottom
            */
            margin-left: 200px;
            margin-top: 50px;
            margin-bottom: 100px;
            width: 200px;
            height: 200px;
            border: 1px solid;
             /*border-left: 1px solid;*/
            padding: 6px;
       }

       .boxer{

           width: 200px;
           height: 100px;
           border: 1px solid;
           margin-top: 200px;


       }
  </style>
</head>
<body>

<div class="box">

  hello
</div>


<div class="boxer">


</div>

</body>
</html>